Adults who received the bivalent RSV prefusion F (RSVpreF) vaccine, compared with no vaccine, had a lower incidence of hospitalizations for respiratory syncytial virus (RSV)-related respiratory illness, based on expanded findings from the DAN-RSV trial presented at ESC Congress 2026 and simultaneously published in NEJM Evidence.

The first year of the DAN-RSV trial randomized adults over the age of 60 years from Denmark to either the RSVpreF vaccine or no vac­cine. Eligibility was expanded in the second year to include adults over 18 years from both Denmark and Spain. In both cases, the primary endpoint was RSV-related respiratory tract disease (RTD) hospitalization in the intention-to-treat population. Secondary endpoints included RSV-related lower RTD and all-cause RTD hospitalization.

Mats C. Højbjerg Lassen, MD, MSc, PhD, et al., found that based on the expanded results, the incidence rate of RSV-related RTD hospitaliza­tion was 0.16 events per 1,000 person-years in the RSVpreF group vs. 0.55 events per 1,000 person-years in the no vaccine group. This corresponded with an estimated vaccine effectiveness of 70%. Additionally, the incidence of all-cause RTD hospitalization was 11.16 in the RSVpreF group vs. 12.01 events per 1,000 person-years in the no vaccine group. The incidence of serious adverse events was similar across both groups at roughly 2%.

A separate DAN-RSV analysis published in NEJM Evidence from Lassen, et al., evaluated protection for adults 60 years of age or older across two consecutive RSV seasons after a single vaccine dose. Researchers found that the RSVpreF vaccine had a lower incidence of RSV-related RTD compared to no vaccine. Vaccine effectiveness estimates appeared to be lower in the second season compared to the first, they said.

In a prespecified safety analysis examining the risk of myocarditis or pericarditis with RSVpreF vaccination vs. no vaccination published in JACC, Marat Yafasov, MD, et al., found myocarditis or pericarditis to be “exceedingly rare for RSVpreF” and no clear differences between those who received the vaccine and those who didn’t.

Another prespecified analysis in JACC evaluated RSVpreF effectiveness against respiratory and cardiovascular hospitalizations and all-cause mortality according to baseline atrial fibrillation (AFib) status. Results showed the RSVpreF vaccine reduced RSV-related respiratory and cardio-respiratory hospitalizations with no evidence of treatment heterogeneity by AFib status. In the expanded two-season cohort, RSVpreF was not associated with higher mortality among AFib participants, according to Caroline Espersen, MD, et al.

Based on these collective findings, Helen Y. Chu, MD, MPH, and Kirby Erlandson, MD, MBA, note in an editorial comment published in NEJM Evidence, that “determining the optimal timing for re-vaccination continues to remain a priority for future research, particularly for higher-risk groups including immunocompromised individuals or those with underlying cardiopulmonary disease,” they write. “Together, these data provide real-world evidence to support RSV vaccination, while highlighting the need to better define re-vaccination schedules.”

Visit ACC’s ESC Congress 2026 coverage page to explore the latest science and key takeaways shaping cardiovascular care.

Clinical Topics: Cardiovascular Care Team, Prevention

Keywords: ESC Congress, ESC26, Respiratory Syncytial Virus Infections, Respiratory Tract Infections, Vaccines, Hospitalization